They have Very German bloodlines.
Around the time of the second world war, the family's name was Hanover (a German name) and they decided to change it to Windsor (their name today) to make it sound more English because of all the anti-German sentiment going on then.
They are very closely related to Germany's Kaiser Wilhelm II, as well as Russia's last tsar (or "king"), Tsar Nicholas.
Compare photos online of the Kaiser, the Tsar, and England's Kind George V and King George VI. They look like BROTHERS, it's freaky. The Queen actually has living relatives that are a spitting image of those men.
ADDITIONAL NOTE: I misspoke. I meant WWI. And YES THEY WERE HANOVERS, Ron C. Queen Victoria's FATHER's last name was Hanover, hence her name and the family's (REAL) name was Hanover. Thank you, I DO know what I'm talking about. Maybe you should do a little research before accusing people. Go to wikipedia and search for Victoria's family tree.
Father HANOVER Edward Augustus Of, b. 2 Nov 1767, Buckingham, London, England, Great Britain
Mother OF SAXE-COBURG Victoria Mary Louisa, b. 17 Aug 1786, Coburg, , Germany